Patents by Inventor Huy M. Nguyen

Huy M. Nguyen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20090278565
    Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.
    Type: Application
    Filed: July 20, 2009
    Publication date: November 12, 2009
    Applicant: Rambus Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
  • Patent number: 7564258
    Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.
    Type: Grant
    Filed: August 17, 2007
    Date of Patent: July 21, 2009
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
  • Patent number: 7525338
    Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.
    Type: Grant
    Filed: December 13, 2006
    Date of Patent: April 28, 2009
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
  • Publication number: 20090034344
    Abstract: A data system component having a state machine circuit and receivers that utilize high and low threshold signals permits accurate detection of strobe signal pattern edges such as those for preamble, burst and post-amble conditions in the strobe signal. The state machine circuit may then be configured to set conditions associated with further circuit elements such as for power saving, data reception, on-die termination, etc. based on the conditions detected in the strobe signal to improve data or memory system performance. The components may be implemented as part of memory controllers and/or memory such as a dynamic random access memory and used in memory read and write operations.
    Type: Application
    Filed: July 24, 2008
    Publication date: February 5, 2009
    Applicant: Rambus, Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Bret G. Stott
  • Patent number: 7439789
    Abstract: Described are controllable termination impedances that may be adjusted collectively by a combination of digital and analog signals. Each adjustable impedance, responsive to the digital signals, establishes a gross termination resistance for one of a plurality of communication channels by enabling one or more of a plurality of parallel-coupled impedance legs. Each leg includes at least one transistor for controlling the impedance of the leg over a continuous range. An analog compensation voltage is level shifted and the resulting level-shifted signal is applied to the control terminals of the transistors of the selected impedance legs. The compensation voltage, and consequently the level-shifted signal, varies with supply-voltage and temperature fluctuations in a manner that causes the collective impedance of the selected legs for each channel to remain stable despite the fluctuations.
    Type: Grant
    Filed: March 7, 2007
    Date of Patent: October 21, 2008
    Assignee: Rambus Inc.
    Inventor: Huy M. Nguyen
  • Publication number: 20080211536
    Abstract: Described are amplifiers that facilitate high-speed communication with calibrated drive strength and termination impedance. Drivers and termination elements can be divided into a number N of parallel portions, one or more of which can be disabled and updated without interfering with signal (e.g., clock or data) transmission. Some embodiments identify inactive elements by examining incoming signals.
    Type: Application
    Filed: May 7, 2008
    Publication date: September 4, 2008
    Inventors: Huy M. Nguyen, Vijay Gadde, Sivakumar Doriaswamy
  • Patent number: 7389194
    Abstract: Described are amplifiers that facilitate high-speed communication with calibrated drive strength and tennination impedance. Drivers and termination elements can be divided into a number N of parallel portions, one or more of which can be updated while signals (e.g, clock or data) are transmitted. Some embodiments identify elements in a high-impedance state by examining incoming signals.
    Type: Grant
    Filed: July 6, 2005
    Date of Patent: June 17, 2008
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Sivakumar Doraiswamy
  • Patent number: 7199605
    Abstract: An apparatus is described having a feedback loop. The feedback loop has an output that approaches a steady state as a data line voltage approaches a reference voltage. The apparatus also includes a driving transistor that drives the data line. The driving transistor has an output impedance that is controlled by the feedback loop output, the feedback loop output keeps the driving transistor output impedance within a high output impedance region when the feedback loop output reaches the steady state.
    Type: Grant
    Filed: June 1, 2005
    Date of Patent: April 3, 2007
    Assignee: Rambus Inc.
    Inventors: Leung Yu, Roxanne T. Vu, Benedict C. Lau, Huy M. Nguyen, James A. Gasbarro
  • Patent number: 7196567
    Abstract: Described are controllable termination impedances that may be adjusted collectively by a combination of digital and analog signals. Each adjustable impedance, responsive to the digital signals, establishes a gross termination resistance for one of a plurality of communication channels by enabling one or more of a plurality of parallel-coupled impedance legs. Each leg includes at least one transistor for controlling the impedance of the leg over a continuous range. An analog compensation voltage is level shifted and the resulting level-shifted signal is applied to the control terminals of the transistors of the selected impedance legs. The compensation voltage, and consequently the level-shifted signal, varies with supply-voltage and temperature fluctuations in a manner that causes the collective impedance of the selected legs for each channel to remain stable despite the fluctuations.
    Type: Grant
    Filed: December 20, 2004
    Date of Patent: March 27, 2007
    Assignee: Rambus Inc.
    Inventor: Huy M. Nguyen
  • Patent number: 7161400
    Abstract: A circuit and method for synchronized clocking of components such as registers. Registers are clocked by individual component clock signals having the same frequency but potentially different phases due to differing propagation delays. Separate component clock signals are received by registers are brought into phase by evaluating the phases of the component clock signals at the registers, and synchronizing the component clock signal of each register to that of the previous register in a sequence.
    Type: Grant
    Filed: October 13, 2004
    Date of Patent: January 9, 2007
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Benedict C. Lau, Leung Yu, Jade M. Kizer
  • Patent number: 7151390
    Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.
    Type: Grant
    Filed: April 6, 2005
    Date of Patent: December 19, 2006
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
  • Patent number: 7135903
    Abstract: A phase-jumping locked loop circuit. The locked loop circuit includes a plurality of differential amplifiers and a biasing circuit switchably coupled to each of the differential amplifiers. Each of the differential amplifiers has inputs to receive a respective pair of clock signals and outputs coupled to a common pair of output signal lines. The biasing circuit comprising a first plurality of biasing transistors coupled in parallel with one another and in series with a first set of the differential amplifiers, and a second plurality of biasing transistors coupled in parallel with one another and in series with a second set of the differential amplifiers.
    Type: Grant
    Filed: February 25, 2003
    Date of Patent: November 14, 2006
    Assignee: Rambus Inc.
    Inventors: Jade M. Kizer, Benedict C. Lau, Roxanne T. Vu, Huy M. Nguyen, Leung Yu, Adam Chuen-Huei Chou
  • Patent number: 7099786
    Abstract: A receiving unit may implement voltage compensation using a parameters table, an analog calibration component, and/or a digital calibration component. In certain implementation(s), an integrated circuit may include a voltage driver that modifies a supplied compensated voltage based on a feedback signal. The feedback signal may be produced responsive to a distributed voltage version of the compensated voltage, to a received data signal, and to a comparison involving an expected data value. In other implementation(s), a parameters table may be initialized by storing calibration values in entries in association with respective multiple identifications of multiple external points.
    Type: Grant
    Filed: February 24, 2005
    Date of Patent: August 29, 2006
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Benedict C. Lau
  • Patent number: 7046078
    Abstract: An integrated circuit has one or more components that operate with reference to a distributed reference voltage. A reference voltage driver produces a compensated reference voltage, and the compensated reference voltage is distributed to form the distributed reference voltage at the components. Due to factors such as trace resistance and gate leakage, the distributed reference voltage is degraded relative to the compensated reference voltage. The reference voltage driver is responsive to feedback derived from the distributed reference voltage to adjust the compensated reference voltage so that the distributed reference voltage is approximately equal to a nominal reference voltage.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: May 16, 2006
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Benedict C. Lau, Adam Chuen-Huei Chou, Roxanne T. Vu
  • Patent number: 7015721
    Abstract: An improved, open-loop push-pull driver is described. Closed-loop feedback loop techniques for control of the push-pull driver are described. These techniques are particularly well adapted to control shoot-through current in a push-pull driver circuit.
    Type: Grant
    Filed: August 24, 2004
    Date of Patent: March 21, 2006
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Benedict Lau, Roxanne Vu
  • Patent number: 7002367
    Abstract: An apparatus is described having a feedback loop. The feedback loop has an output that approaches a steady state as a data line voltage approaches a reference voltage. The apparatus also includes a driving transistor that drives the data line. The driving transistor has an output impedance that is controlled by the feedback loop output, the feedback loop output keeps the driving transistor output impedance within a high output impedance region when the feedback loop output reaches the steady state.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: February 21, 2006
    Assignee: Rambus, Inc.
    Inventors: Leung Yu, Roxanne T. Vu, Benedict C. Lau, Huy M. Nguyen, James A. Gasbarro
  • Patent number: 6924660
    Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.
    Type: Grant
    Filed: September 8, 2003
    Date of Patent: August 2, 2005
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
  • Patent number: 6897713
    Abstract: An integrated circuit has one or more components that operate with reference to a distributed reference voltage. A reference voltage driver produces a compensated reference voltage, and the compensated reference voltage is distributed to form the distributed reference voltage at the components. Due to factors such as trace resistance and gate leakage, the distributed reference voltage is degraded relative to the compensated reference voltage. The reference voltage driver is responsive to feedback derived from the distributed reference voltage to adjust the compensated reference voltage so that the distributed reference voltage is approximately equal to a nominal reference voltage.
    Type: Grant
    Filed: February 14, 2002
    Date of Patent: May 24, 2005
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Benedict C. Lau, Adam Chuen-Huei Chou, Roxanne T. Vu
  • Patent number: 6876248
    Abstract: A receiving unit may implement voltage compensation using a parameters table, an analog calibration component, and/or a digital calibration component. In certain implementation(s), an integrated circuit may include a voltage driver that modifies a supplied compensated voltage based on a feedback signal. The feedback signal may be produced responsive to a distributed voltage version of the compensated voltage, to a received data signal, and to a comparison involving an expected data value. In other implementation(s), a parameters table may be initialized by storing calibration values in entries in association with respective multiple identifications of multiple external points.
    Type: Grant
    Filed: May 28, 2002
    Date of Patent: April 5, 2005
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Benedict C. Lau
  • Patent number: 6861884
    Abstract: A circuit and method for synchronized clocking of components such as registers. Registers are clocked by individual component clock signals having the same frequency but potentially different phases due to differing propagation delays. Separate component clock signals are received by registers are brought into phase by evaluating the phases of the component clock signals at the registers, and synchronizing the component clock signal of each register to that of the previous register in a sequence.
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: March 1, 2005
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Benedict C. Lau, Leung Yu, Jade M. Kizer